Windows usually feels ugly if you have a bad monitor (which is pretty much 99.9% of the monitors available in the market today).

I've recently bought an Asus Rog Swift monitor and I couldn't be happier with Windows.

https://www.amazon.com/27-inch-Monitor-PG278Q-Response-Displ...

UI itself is just a matter of preference and I don't mind Windows 10 UI, you can hide most of the things you find ugly.